add authorization

lib/pages/auth_page.dart

@@ -0,0 +1,60 @@
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+import 'package:local_auth/local_auth.dart';
+import 'package:venera/utils/translations.dart';
+
+class AuthPage extends StatefulWidget {
+  const AuthPage({super.key, this.onSuccessfulAuth});
+
+  final void Function()? onSuccessfulAuth;
+
+  @override
+  State<AuthPage> createState() => _AuthPageState();
+}
+
+class _AuthPageState extends State<AuthPage> {
+
+  @override
+  Widget build(BuildContext context) {
+    return PopScope(
+      canPop: false,
+      onPopInvokedWithResult: (didPop, result) {
+        if (!didPop) {
+          SystemNavigator.pop();
+        }
+      },
+      child: Material(
+        child: Center(
+          child: Column(
+            mainAxisSize: MainAxisSize.min,
+            children: [
+              const Icon(Icons.security, size: 36),
+              const SizedBox(height: 16),
+              Text("Authentication Required".tl),
+              const SizedBox(height: 16),
+              FilledButton(
+                onPressed: auth,
+                child: Text("Continue".tl),
+              ),
+            ],
+          ),
+        ),
+      ),
+    );
+  }
+
+  void auth() async {
+    var localAuth = LocalAuthentication();
+    var canCheckBiometrics = await localAuth.canCheckBiometrics;
+    if (!canCheckBiometrics && !await localAuth.isDeviceSupported()) {
+      widget.onSuccessfulAuth?.call();
+      return;
+    }
+    var isAuthorized = await localAuth.authenticate(
+      localizedReason: "Please authenticate to continue".tl,
+    );
+    if (isAuthorized) {
+      widget.onSuccessfulAuth?.call();
+    }
+  }
+}